In a situation where multiple cameras capture or are able to capture images of one another, information indicating positional relationships among these cameras can be useful.
For example, in a case where moving objects (e.g., people) are each equipped with a wearable camera and perform image capturing while moving around (e.g., each participant of a meeting or a party wearing a camera), each camera may change its image-capturing subject from time to time without capturing a particular subject continuously. In this case, a review of a captured image does not provide a user with information on what is not captured in the image, such as what is hidden behind an object captured in the image. However, if positional relationships among the cameras are known, the user can easily identify which camera is capturing what is behind the object, and also can have a view of the place where the image-capturing is performed, from a different angle.
While the above is merely one example of an advantage, information indicating positional relationships among cameras can be available for various uses, and accordingly, there is a need to facilitate generation of such information.
To fulfill the need, the following methods may be applied.
For example, positions of the cameras in a global coordinate system are determined using base stations conducting a wireless communication or using GPS (Global
Positioning System). Once the positions of the cameras in the global coordinate system are determined, positional relationships among the cameras can be calculated with use of the determined positions. It should be noted that a technique for determining current positions using base stations is disclosed in Patent Documents 1 and 2 below.
Patent Document 1: Japanese Patent Application Publication No. H10-239416
Patent Document 2: Japanese Patent Application Publication No. 2005-86579